169.331.  Retired teachers may teach full time without loss of benefits, when — school district requirements. — 1.  Notwithstanding any other provision of sections 169.270 to 169.400 to the contrary, a retired certificated teacher receiving a retirement benefit from the retirement system established pursuant to sections 169.270 to 169.400 may, without losing his or her retirement benefit, teach full time for up to four years for a school district covered by such retirement system; provided that the school district has a shortage of certified teachers, as determined by the school district.  The total number of such retired certificated teachers shall not exceed, at any one time, thirty certificated teachers.

  2.  The employer's contribution rate shall be paid by the hiring school district and the employee's contribution rate shall be paid by the employee.

  3.  Any additional actuarial costs resulting from the hiring of a retired certificated teacher pursuant to the provisions of this section shall be paid by the hiring school district.

  4.  In order to hire teachers pursuant to the provisions of this section, the school district shall:

  (1)  Show a good faith effort to fill positions with nonretired certificated teachers;

  (2)  Post the vacancy for at least one month;

  (3)  Have not offered early retirement incentives for either of the previous two years;

  (4)  Solicit applications through the local newspaper, other media, or teacher education programs;

  (5)  Determine there is an insufficient number of eligible applicants for the advertised position; and

  (6)  Declare a critical shortage of certificated teachers that is active for one year.

  5.  Any person hired pursuant to this section shall be included in the State Director of New Hires for purposes of income and eligibility verification pursuant to 42 U.S.C. Section 1320b-7.